Bag filling and weighing machine



March 27, 1951 F. F. LINDSTAEDT ETAL 2,543,193

BAG FILLING AND WEIGHING MACHiNE Filed June 13, 1947 4 Sheets-Sheet 1 INVENTORS Frank F. Lindsvaec/f By Charles R. Fischer" ATTORNEY March 1951 F. F. LINDSTAEDT ETAL 2,546,193

BAG FILLING AND WEIGHING MACHINE Filed June 13, 1947 4 Sheets-Sheet 2 INVENTORS Frank fi L/ndsfae d7 Char/es R. Fischer March 27, 1951 F. F. LINDSTAEDT ETAL 2,546,193

BAG FILLING AND WEIGHING MACHINE Filed June 15, 1947 4 Sheets-Sheet 3 INVENTORS Frank E. L/ndsfaedf BY Char/e5 A. Fischer ATTO NE) March 27, 1951 F. F. LINDSTAEDT ET AL 2,546,193

BAG FILLING AND WEIGHING MACHINE Filed June 13, 1947 4Sheets-Sheet 4 Pas/Tl v5 TERM/MAL NEGATIVE ERM/NAL INVENTORS Frank E L/hasfaeaf BY Char/e5 17. Fischer ATTORNEY Patented Mar. 27, 1951 BAG FlLLllNG AND WEIGHING MACHINE- Frank F. Lin'dstaedtl. San Anselmo, and Charles R:' Fischer, Corie Madera, Calif. 'said Fischer assignorto- SeImer A. Melbostad, San Fran ciscc, Calif;

Application J ime 13, 1947, Serial-No. 754,490:

The present invention relates'to improvements in a bag" filling andweighing,machine andiits sired weight; releases the bagand" returns all the active'parts to an initial position for repetition of the operations" in a continuous" cycle.

Our invento'n is particularly intended for feeding desired weightsof potato chips in so-called waredpaper bags; and one of th'e'problems'solved in the present invention is the -mounting of' a pluralityof Waxed paperbagsins'ucha manner that'they are made" accessible successively for gripping action by a" gripping element.

It is further proposed t'o'use a suction element for successively gripping the bags in such a: man--' ner that each bag, upon'bei'ng' gripped, forms a seal for the gripping element'andthereby sets in motion other suction-operated mechanism for moving the bag into position" with resp'ect'toa feeding hopper.

Bags of this character are made of two sheets o mat -rial; one of which has a-=flap proiecting above the other sheet, anditis further proposed to provide an abutm nt onth'e' hopper-or a ole-- pending c ute to engage the'fiap of the' bag -for opening the latter during its advance and-to thread the bag on the hopper in a'c'ontinuous movement.

t is further proposed to provide meansfor releasing the bag-from its carrier after the'bag has reached an op'erative position with respect to the chute, to lock the bag in such positiomto move the carrier into an out-of-the-way'position and 'to' simultaneously start:- the feeding-' meansi Andi finally; it is proposed to provide means for automatically arresting the feeding means,

when'the has been: fille'd to 'a" desired weight, release the bag and to automatically return:

the carrier to aninitial position-for the" next cycle 01 operations.

Further obj acts? and advantages of our inven-- tion will appear as the specificationproce'eds, and the novel features? oi -our invention will be fully defined:in the claims atta'ched herettt The preferred form of our invention is illustrated in the accompanying drawing, in which Figure 1 shows a side elevation of our machine, with the different parts-presented in starting position;

Figure 2, a similar side elevation with'the parts presented in their respective positions when the bag is filled to a desired weight;

Figure 3-, a horizontal section taken along line 3'3 of Figure 1;

Figure 4, a horizontal section taken along line 44 of Figure 1;

Figur v 5, a transversesection taken along line 55 of Figure 1;

Figure 6, a horizontal section taken along line 5-5 of Figure 1; and

Fi ure 7, a wiring diagram.

While we have shown only the preferred form of our invention, we Wish to have it understood that various changes and modifications maybe made within the scope of the claims attached hereto without departing from the spirit of the invention.

Referring to the drawings in detail, our machine comprises in its principal features a magazine l for holding a plurality of bags, a suction arm or tube 2 with attendant mechanism for gripping and moving the bags, a hopper 3 'for guiding material to the bags, a vibrator 4 for feeding the material, and a weighing machine 5 from which the hopper is suspended.

The magazine I is preferably made in the form of a channel-shaped trough 5 with a flat bottom I and flat sides 8 mounted on opposite sides thereof. The width of the trough should correspond substantially to that of the bag so that a stack of bags may b received in the magazine, with the bags in upright position and free to slide toward the front of the magazine. At the latter end we provide two corner posts 9 on opposite sides of the trough for the foremost bag to rest against. The two corner posts are located close to the sides and leave the main portion of the bag uncoveredso that the foremost bag may be easily withdrawn by the suction tube through the gap between the posts.

The bottom I of the trough is hinged, as at l0, near the front end of the magazine so that it may be swung upward, after the bags have been positioned, preferably through an angle of 15 to 3'0 degrees. This upward swing causes slight relative. motion'between the bags comparable to that of the'leaves of a book when the latter'is opened, andtends to break adhesion between the bags. It also induces. a natural forward movement of .all the: bags; when the: foremost bag: is

removed and causes the second bag to automatically slide into the place previously occupied by the removed bag. A pendulum weight i is made to bear on the back of the rearmost bag for holding the stack of bags in upright position, this weight being supported on a cross-bar l2 slidable on the upper edges of the magazine. The magazine is mounted on a slight angle as shown and the bar tends to follow the diminishing stack under the influence of gravity.

The bags under consideration are conventional waxed paper bags comprising two flat side walls with a flap of the rear wall projecting beyond the front wall. They are mounted in the magazine with the front wall presented forwardly.

The hopper 3 is suspended from the balancing member E3 of the weighing machine 5, which latter is supported on a frame structure comprising four legs l4 and top frame members 85. The balancing member is pivoted on a post it, has a suitable weights ll mounted on the long rear arm thereof and has rods l8 suspended from the short arm by means of a plate E9, the hopper being attached to the rods with freedom of adjustment as at 20.

The hopper 3 has a tubular chute 2i dependin therefrom, the lower portion of the tube being cut at an angle as at 22 to present a small bottom section or lip 23 facing the upper portions of the assembled bags. The hopper, when in raised position, as in Figure l, is disposed such a manner that when the foremost bag is pulled forward in a manner to be hereinafter described, the front section of the bag is free to pass the lip 23 while the projecting rear flap of the bag catches behind the lip 23. Ihis causes the bag to be opened and renders the bag free to move upward on the chute as the forward movement of the bag is changed into an upward swing. Thus the bag is made to encircle the chute in material receiving position and when the bag reaches its final position, with its upper end substantially at the bottom line of the hopper, it is locked by means of a spring 25 operated by a solenoid 26, which will hereinafter be referred to as the hopper solenoid.

The foremost bag in the magazine i is picked up and moved in the desired direction by means of the suction arm 2 with its operating mechanism mounted on an intermediate frame 2%. suction arm is tubular in form and is mounted, at its rear end, on a link 23 swingable on a base 29, and intermediate its length on a toggle joint in cluding the two links 3i? and Si pivoted together as at 32, the former link being pivoted to the frame as at 33 and the latter link being pivoted to the suction arm 2 as at 34.

For balancing the suction arm to produce a desired compound movement, we use a bar 35 pivoted to a frame member .24 and having a roller 36 hearing on a Wedge 3i mounted underneath the arm while the front end, which extends up ward in a slanting direction forwardly of the pivot, carries a weight 38 adjustable in a slot This arm with its weight exerts a lifting efiect on the suction arm and aids in the lifting arm, thus allowing of the use of a relatively small piston and piston chamber. It may be omitted if a larger piston is used for raising the suction arm.

The arm is operated by a piston movable in the cylinder 40, which latter is mounted with freedom of swinging motion in a vertical plane on the axis 4|, the piston being suction-operated and being connected to the toggle joint at the pivot 32, by means of a piston rod 42.

The 1 A suction.

line 43 controlled by a valve operated by the solenoid 44 is connected to the arm, and a branch 43 of the line is connected to the suction chamber of the cylinder 453, so that as long as the forward end of the suction arm remains open, no suction will be applied to the piston, but when the suction arm is closed by a bag gripped by the latter, suction will be applied to the piston and will set in operation the arm-operating mechanism.

It is apparent that when no bag is available for closing the end of the suction arm, no suction will be applied to the arm and the mechanism will stop automatically.

The arm, which normally rests on a roller 45 to positively limit its downward swing, is dragged forward, into contact with the foremost bag in the magazine, by means of a spring 46 acting on the link 30, and just before its forward end reaches the bag the link 28 closes a micro-switch 4? which again closes a magnetic switch 48, which in turn closes the circuit of the vacuum solenoid 44, opening the suction valve.

The suction in the suction arm grips the foremost bag and the latter seals the front end of the suction arm. The arm being sealed, the suction now becomes active on the piston in the cylinder 40, and the piston rod pulls on the pivot 32 of the toggle joint, tending to draw the latter backward. This causes the suction arm, due to the balancing member 35, to first retract endwise through a short distance and then to swing upward toward the position shown in Figure 2.

During the retracting movement the suction arm pulls the foremost bag out of the magazine and brings the rear flap of the same opposite the lip 23 of the hopper chute for opening the bag. Immediately thereafter-the arm begins its upward swing along the angular cut 22 of the chute and threads the bag upon the chute.

During the first part of the retracting movement of the suction arm the link 28 opens the micro-switch 4?, but this leaves the magnetic switch 48 unaffected so that suction continues on the piston to effect the compound movement of the arm.

As the bag approaches its end position, with its upper end approximately adjacent the bottom line of the hopper, its rear wall slips underneath the spring 25, and after the bag reaches its end position the following operations take place:

1'. The suction arm closes a second microswitch 49. This opens the magnetic switch 48 which de-energizes the vacuum solenoid 44 and relieves suction on the piston.

2. The closing of the micro-switch 49 also causes a second magnetic switch 50 to close across two sets of contacts, designated as a,b and c-d respectively.

Contacts ab are in circuit with a solenoid 5!, the armature 52 of which is connected, through a link 53, to the lower arm 30 of the toggle joint, and when suction in the suction arm and on the piston in the cylinder 40 ceases, with the bag in final loading position, the armature 52 takes over and pulls the suction arm, now released from the bag, still higher and into an out-of-the-way position.

At the same time contacts c-d close the circuit of the hopper solenoid 26 and cause the spring 25 to bear down on the bag for locking the same in position.

3. The suction arm closes a third micro-switch 54 which is connected into the circuit of the vibrator 4..- and starts operation ofi'the latter: The

vibrator: is. of conventional. type, receives mate-. rial from a chute 55Jand,.vibratessthesame'into= thezhopper13 'forfeeding into the bag? When the bag has received the .desiredamount of 'material, the balancing. elementof theweighing: machine yields to. the .combinedweight-of. the hopperiand the .bag'andi tips on'itsL-pivot l6; The balancing? element carries a. mercoid: switch 56' which; tips, with the latter." The mercoid switchhas two-sets-of contacts at opposite ends thereof, thetwo sets beingmarke'd e and f respectively. The contacts e form part of the :viorator circuit and are closed during the filling operation. When the balancing member tips under the weight. of the-filled1 bag,v the mercury runs to the other end: of the tube, and in. this operation first opensthev contacts atie,-,thereby stopping the vibrator, andcthen closes. the contacts at-f. The latter contacts. are 'part' of a' circuit operable to reverse the position of themag netic switch 50 opening, the circuit of the solenoid 5| at 0-12 so as toallow thesuction armto drop back, and that of the hopper solenoidlat c d. so asto allowlthe bag to drop.-

Since'the operation described in the preceding paragraph. dependssuponthebag receiving apredetermined amount of material, it is apparent that the machine will stop automatically when no material is available for feeding the bag.

The operationof our machinemay be further explained by reference to the. Wiring diagram of Figurefi.

The main. line wiresare indicated. at elk-El and. lead; through a main switch .62, tothe posi-- tive and negative terminals 63 and $4 respec tively.-

As the. suction arm, 2 advances-toward the foremost bag and. comes Within a short distance of the same, say-about. -of.-an inch, the link 28- closes the micro-switch. andcauses a cur-- rentto flow from positiveterminal 63 throughwire 65, coil 66, wire 61, micro-switch 41 and wire 68. to the negative terminal 64. 'I'hisclosesemagi netic switch48 across the contactsBB.

A current then flows from the. positive terminal 63.through wire 10, vacuum-solenoid 44,. wire H, magnetic switch 48- and. wire 12 to-the negative 64fopening the suction valve of the vacuum. solenoid.

Suctionisthen applied through the pistonchamber of- .cylinder 40 tothesuction arm: 2, and as the forward end of the arm contactsthe'foremost bag, the suction grips the latter and the suction arm issealed-by the bag.-. With the suc tion arm sealed, the'suction becomes-active on.

opens the micro-switch '41-, but this does not're-e' lievev suction, since the magnetic. switch 48' re-.

mains closed it requiringenergizing of coil l3 to. openthe same.

Before the bag reaches the proper material receiving position, the rear wall of thebag slips under spring. 25, and immediately thereafter the suction arm closes-micro-switch 49.

Acurrentnow flows from the positive terminal 63 through. wi1'e.'65,. coil .13, wire l4, micro-- switch. 49. and. wire 15: to the. negative terminal.

64, the coil 33 openingsmagneticl valve: 481 and reelievin suction in the suction arm whereby the;

latter is made to'release the bag;

At the same time a current" flows' from' thepositive terminal tie-through wire 16, coil 11', wire 18, wire M, micro-switch 49 and: wire 15 to the negative 54. The coil Tllcloses: magnetic switch SKI/across both sets of contacts ab and;

A current then flows from the positivetermi-- nal63 through wire 19, solenoid 5|, wire 80, contact-se m, wire H micro-switch49 and wirel5 backto the negative terminal 64. This current energizes solenoid. 5|, which, throughthe links 53 and. 30, continues the upward swing of the suction arm for. a short distance and pulls the arm into an: out-of-the-way position so as to clear the bag. The arm is securely held in this position until the bag is. filled 'to the'de'sired weight, and if for some reason: feeding of thematerial should be stopped, the arm remains in that position.

At the same time acurrent flows through con tacts c-d, the complete circuit comprising the; positive terminal 63, wire it, wire- 83, hopper per solenoid 25, which latter, bearing on: the

spring 25, causes the same'torclo'se uponithe. bag for locking the latterinmaterialereceivingi'posi-. tion.

Substantially at the same. time; possibly a.

fraction ofa second later; depending'upon adjustment, the upwardswingof the suctionarrn closes":

the micro-switch 54, causing a current to flow from the main switch 62 through'wire 82; a. vi-- brator rheostat 83, wire 84," the vibrator 4, wire" 85, contacts e'of the mercoid switch, wire 86',

micro-switch 5d, wire 15,- negative terminal lit This.

and Wire backsto the main switch 62. current actuatcs the vibrator 4' to start feeding material into the hopper and intozthe bag suspended therefrom.

Summarizing. briefly, when theisuction arm 2,1.

on'its upward swing, reaches bag-releasing posi' tion, the electrical circuits describedrelieve-suction to-release the bag, pull the arm-into an out-cf the way, bag clearing position, applyv the spring 25 for locking the bag to thechute andstert operation of the vibrator.

After the bag has received the desired weight. of material, the balancing member l3 of the weighing machine tips under. the combined weight of thehopper andthe filled bag; causing the mercoid switch to tilt from an inclined posi-- tion through ahorizontal position into an -op-- positely inclined position. While the switch moves through thehcrizontal position, the contacts at e are disconnected for opening the vi-- iich the contacts forma part,.

brator circuit, of as-previously described. i'hus the feeding of material stops slightly before the next eoperae tions take place.

As the tilting movement of the-mercury switch is continued, the mercury connects the contacts at f. This energizes coil- 87 of the magnetic switch 5 to disconnect contacts a-b and cd current flowing from positive terminal tit-through wire 'lii, coil 8t, wire 88, mer

cold switch contacts 7 and wire' 89 back-to the negative terminal. Disconnecting. contacts cd breaks circuit of the hopper solenoid 26 and if at 9!. Disconnecting contacts ab breaks the circuit of the solenoid i and allows the suction arm 2 to drop back upon the roller 55. Suitable means may be provided for retarding the drop of the arm, if desired.

We claim:

1. In a bag filling machine of the character described, a hopper having a depending chute, means for moving a bag having a projecting flap with respect to the chute to cause the flap to catch behind the bottom edge of the chute for opening the bag, the said means being operable to guide the open end of the bag over the chute and to release the bag when the latter has reached a desired position with respect to the chute, and independent means for locking the bag to the chute when the first means releases the bag.

2. In a bag filling machine of the character described, means for mounting a bag accessible for gripping action, a suction arm movable lengthwise toward the bag, and suction operated means for retracting the arm connected to the arm for producing suction therein so as to re main inactive for retracting the arm as long as the advance end of the arm remains open, the bag being operable upon contact for closing the end of the arm and for rendering the arm retracting means active.

3. In a bag filling machine of the character described, means for mounting a bag accessible for gripping action, a suction arm movable lengthwise toward the bag, and suction operated means for retracting the arm connected to the arm for producing suction therein so as to remain inactive for retracting the arm as long as the advance end of the arm remains open, the bag being operable upon contact for closing the end of the arm and for rendering the arm retracting means active, and the retracting means including means for swinging the arm into angular position after a desired amount of retracting movement.

4. In a bag filling machine of the character described, means for mounting a bag accessible for gripping action, a suction arm movable lengthwise toward the bag, and suction operated means for retracting the arm connected to the arm for producing suction therein so as to remain inactive for retracting the arm as long as the advance end of the arm remains open, the bag being operable upon contact for closing the end of the arm and for rendering the arm retracting means active, and the retracting means including means for swinging the arm into angular position after a desired amount of retracting movement, and means for relieving suction after a desired angularity has been reached.

5. In a bag filling machine of the character described, means for mounting a bag accessible for gripping action, a suction arm movable lengthwise toward the bag, and suction operated means for retracting the arm connected to the arm for producing suction therein so as to remain inactive for retracting the arm as long as the advance end of the arm remains open, the bag being operable upon contact for closing the end of the arm and for rendering the arm retracting means active, and the retracting means including means for swinging the arm into angular position after a desired amount of retracting movement, and means for relieving suction after a desired angularity has been reached, with independent means for continuing the swinging movement of the arm after the suction ceases.

6. In a bag filling machine of the character described, a suction tube open at one end thereof, a piston having connection with the tube for moving the same, and a common means for applying suction to the tube and the piston whereby the tube is made to attract and grip a sealing member arranged opposite the open end thereof and the piston is made to move the tube in response to the sealing of the open end thereof.

7. In a bag filling machine of the character described, a. suction tube open at one end thereof, a link mechanism supporting the tube with freedom of compound movement, a piston operating the link mechanism, and a common means for applying suction to the tube and the piston whereby the tube is made to attract and grip a sealing member disposed opposite the open end thereof, and the piston is made to move the tube in response to the sealing of the open end thereof.

8. In a bag filling machine of the character described, a suction tube open at one end thereof, means for supporting the tube with freedom of endwise movement followed by a swinging movement, means for mounting a bag opposite the open end of the tube, means for producing suction in the tube, and means for advancing the tube toward the bag including means for rendering the suction means active when the tube reaches a predetermined position with respect to the bag.

9. In a bag filling machine of the character described, a suction tube open at one end thereof, means for supporting the tube with freedom of endwise movement followed by a swinging movement, means for mounting a bag opposite the open end of the tube, means for producing suction in the tube, means for advancing the tube toward the bag including means for rendering the suction means active when the tube reaches a predetermined position with respect to the bag so as to grip the bag upon contact and to seal the tube, and means operable in response to the sealing of the tube for initiating a swinging movement of the tube.

10. In a bag filling machine of the character described, a suction tube open at one end thereof, means for supporting the tube with freedom of endwise movement followed by a swinging movement, means for mounting a bag opposite the open end of the tube, means for producing suction in the tube, means for advancing the tube toward the bag including means for rendering the suction means active when the tube reaches a predetermined position with respect to the bag so as to grip the bag upon contact and to seal the tube, and means operable in response to the sealing of the tube for initiating a swinging movement of the tube, the latter means having means cooperable therewith for relieving the suction when the arm reaches a predetermined position and for continuing the swinging movement of the tube to a bag clearing position.

11. In a bag filling machine of the character described, a suction tube open at one end thereof,

means for supporting the tube with freedom of.

endwise movement followed by a swinging movement, means for mounting a bag opposite the open end of the tube, means for producing suction in the tube, means for advancing the tube toward the bag including means for rendering the suction means active when the tube reaches a predetermined position with-respect to the bag so as to grip the bag upon contact and to seal the tube, and means operable in response to the sealing of the tube for initiating a swinging movement of the tube, the latter means having means cooperable therewith for relieving the suction when the arm reaches a predetermined position and for continuing the swinging movement of the tube to a bag clearing position, with independent means for gripping the bag when the latter is released by the tube.

FRANK F. LINDSTAEDT,

CHARLES R. FISCHER.

REFERENCES CITED The following references are of record in the file of this patent:

Number 10 UNITED STATES PATENTS Name Date Price June 11, 1901 Cox Sept. 23, 1913 Beckmann Mar. 20, 1917 Frank June 22, 1926 Dalton Mar. 1, 1938 Sackett Nov. 24, 1942 Nowak, Jr Jan. 25, 1944 Peterson June 6, 1944 Orstrom Mar. 2, 1948 

